The conventional practice of administering a gaseous anesthetic to a patient about to receive a minor surgical treatment has generally included the placement of a breathing tube in the supine patient prior to manipulating the patient into a face-down, or prone position. This procedure has been adopted to avoid relinquishing control of the airway of an anesthetized patient. As a result, certain types of operations performed on the backside of a patient have typically used a general anesthetic with insertion of a breathing tube prior to rotating the patient to the prone position. At the conclusion of the surgical procedure, the patient is returned to the supine position. The manipulation of the anesthetized patient without his cooperation is not easy for any patient and cannot be accomplished by one person.
A substantial number of operations are performed with the patient in the prone position. If many of these operations can be performed without the use of a general anesthetic, the breathing tube and the need to change the positions of an anesthetized patient can be substantially reduced, as is the amount of time required for the procedure and for use of the operating room. Furthermore, the elimination of the combination of general anesthetic and breathing tube enables the reflexes of the patient to be maintained during the procedure. The patient under sedation rather than general anesthetic manages his own airway. In both cases, a standard facial mask is used to convey oxygen, provide ventilation, and permit monitoring of the respiratory function of a patient.
While the advantages of sedation to permit a cooperating patient to assume a prone position when undergoing certain types of procedures are recognized, the lack of suitable head supporting apparatus that can accommodate a patient wearing a facial mask in a face-downward position has prevented the adoption of this procedure. Among the problems confronting the staff planning to operate with a prone-positioned patient is the importance of maintaining clearance between the face mask and the patient so as to ensure continuous flow of gaseous inhalant and to provide a volumetric region which can receive and retain any emissions from the patient without impeding the flow of gaseous inhalant. In addition, the inhaled gases are supplied through tubing, which must remain free from pressure points, such as snarls, kinks, and any contact pressure from adjacent structural members.